Social Media Expert Jobs - What Are They Really?

Recently when I worked for a TEDx team, "a part" of my job was handling their social media. Everyone on the internet business is talking about 'Social Media Experts' and how they are important.

Well, there are mixed reviews about this job profile.
Some people say :
I WILL NEVER HIRE A “SOCIAL MEDIA EXPERT,” AND NEITHER SHOULD YOU
While others say :
Everyone Should Hire 'Social Media Experts'

The reason why social media has become so successful is because it is driven by the consumer.
Just take a look at one of the most popular social media site on the planet: Facebook.
Social media offers up an opportunity for businesses to follow the chatter around their products; which they might not have been able to tap into traditionally.

We’re only just at the start of this revolution. With the advent of high-speed mobile networks the way we do things will change quickly and for-ever. Social Networking sites are already changing the way we interact with people we may never meet, market ourselves and our companies and sell products and services.

What do you think about social media experts? Do you need one? Would you like to be one?